Polysaccharides are generally classified according to their origin, i.e., from plants, animals and microorganisms. For example, plant polysaccharides include cellulose, pectin, amylose carrageenin, agar-agar and the like; animal, heparin and condroitin-sulfate; and microorganisms, dextrans, xanthan gum, pullan, curdlan and the like. Most such polysaccharides contain glucose as the principal constituent sugar. As is well known, many of the aforesaid polysaccharides are used in industry for many and varied purposes such as thickening agents, stabilizers for foams and the like, emulsifiers, and are widely used in the food, cosmetic and pharmaceutical industry. Polysaccharides can also be used as moldable materials for biodegradable films, as well as flocculating agents since they can be gelled in aqueous solution in the presence of calcium ion.
It is known that species of the genus Pseudomonas produce polysaccharides: Applied Microbiology, published December, 1974, p. 903; Japanese published application Nos. 151392/76; 130594/76 and 21393/77. The main constituent sugar of the polysaccharides so produced is glucose.